The "this is super and excellent" reviews don't tell me much. I look at the bad reviews. Usually you can get an idea if a product is any good by the type of bad review. If there are many good reviews, but one or two saying "delivered late", "wrong product", or "damaged in transit", then I figure that this can happen occasionally but can be sorted out if it does. Some reviews will be bad because of different use-cases ... if most people give high rating for sound quality on a radio but one or two say "distorts at high volume" then you'll probably be OK if you listen at reasonable volumes. Someone once gave a washer/dryer a 2 start review because it took over three hours for a complete wash/dry cycle. For us that didn't matter - we run it a few times a week and just set it going until it ends. Someone might complain about "complicated controls" on an SLR camera or "lack of flexibility" on a point and shoot ... again it might not matter to you.
On the other hand if a lot of people complain about the general quality of an item, or lack of functionality that you would actually use then that's a good reason to stay away from one.